Quarter capsicums; remove seeds and membranes. Cut each piece into three triangles. Slice eggplants in half lengthways, cut each half into large pieces. Place capsicums and eggplant in a large baking dish; toss with half the oil and half thyme.

Halve zucchinis lengthways, cut into large pieces. Cut squash into three slices crossways. Place zucchini, squash, onions and whole bulb of garlic in a large baking dish; toss with remaining oil and thyme.

Bake both dishes, uncovered, in a very hot oven about 20 minutes or until browned and tender, shaking dishes occasionally.